DE2148273C3 - Double exposure control device for a motion picture camera - Google Patents

Description

A double exposure control device for a motion picture camera, the drive motor of which can be reversed in the direction of rotation, with one for double exposure recordings to the motor drive through one operating coupling device which can be coupled to the film length measuring and limiting unit, which, in the coupled state, is proportional to the film transport of having a starting position in an end position movable counting member, the end position by a The limit switch for the drive motor that can be actuated by the counter is defined, is from DE-OS 15 97 345 known.

In the known device, the limit switch ensures that when performing a double exposure, for example for the purpose of a dissolve, the Drive motor is switched off after the first exposure of a defined fiber length. After that, will the drive motor is switched to reverse and the exposed length of film is brought back again. Afterward the motor is switched back to forward direction and the fetched film length to the second times exposed This can then be followed by a normal exposure of another piece of film.

Such double exposures are generally only possible up to a certain maximum film length, because a backstop is usually provided in the film cassette the film take-up shaft stopped during the first exposure and that destined for the double exposure The piece of film is transported further through the film gripper assembly and on the take-up reel side in the film cassette stored loosely in the available space. Since the film length to be accommodated in this way is limited The limit switch ensures that a certain maximum film length cannot be exceeded.

Particularly because of this backstop, it is important to ensure that the double exposure is carried out after the The length of the film retrieved from the first exposure is at most equal to the loosely stored film length previously transported Is the length of the film, otherwise the film perforation or even the entire film will tear

For this purpose, the following measures are provided in the double exposure control device known from DE-OS 15 97 345.

The counting element is designed as a disk that can be rotated out of the starting position in both directions against spring force. She wears a cone that ever according to the direction of rotation of the disk from one side or the other against one of two sides actuatable limit switch is running. With the first exposure of a double exposure, the To turn the counting disc in one direction to finally run up on the limit switch, whereby the Drive motor is switched off. It is then coupled when the drive motor is switched to reverse the coupling of the counting disc to the motor drive is temporarily canceled so that the counting disc is under the Can return to the starting position under the action of their return spring, and then then again to be made. When the motor is switched on again, the counting disk starts to move out of its Starting position to turn out in the other direction of rotation, then from the other side against the To open the limit switch and thus switch off the motor again. A suitable choice of the limit switch position ensures that the angle of rotation at this rotation associated with the return transport of the film is not greater than the previous rotation Rotation of the counting disk in the other direction associated with the first exposure. That way is ensures that no more film is retrieved than has previously been loosely stored.

With the known camera, a dissolve can only ever be done on one and the same length of film take place. For a variety of reasons it is

however, it is desirable to make the film length on which a superimposing takes place variable, in order to achieve better adaptation to the needs of the individual case and better design options when filming. With the known camera, one could think of making the starting position of the counting disk adjustable via an actuator that can be operated from the outside. The adjustability could only be made in such a way that the length of the fused piece is more or less smaller than the length of the film that was previously transported during the first exposure. In this way, the film length on which a double exposure takes place can be varied, but the starting points of the first and second exposure no longer coincide because the starting point of the second exposure is determined by the film length that is retrieved and the later the less film has been retrieved after the first exposure. In particular, overlaying in the sense of a slow fade out ^ and simultaneous slow dimming of the next scene are therefore no longer possible.

You have to vary the duration of the overlay on various occasions by letting go of the button earlier during the first exposure With the shutter release, a correspondingly shorter film length is exposed, which is then used for the second exposure is retrieved (see DE-AS 19 08 975). Another well-known way out was the length of the top panel simply to vary by the fact that the fade-out process and the faded-in process be executed in a correspondingly shortened form, without doing what is intended for overlaying purposes To vary the film length yourself (see CH-PS 4 92 231).

These makeshift measures to vary the effective length of the top cover require some skill and some practice on the part of the operator if errors are to be avoided.

The object of the invention is therefore to provide a different fade length that can be preset in a simple manner to enable, at the same time provision should be made that the deployment points of first and second exposure coincide.

According to the invention, this object for the double exposure control device is that described in the introduction Art solved in that another, the starting position of the counter and assigned by this operable off switch is provided that the end position of the counter for the double exposure defining limit switch is a mounted on the camera body adjustable and relative to the counting element adjustable contact part and one with the counter element moved along with the adjustably mounted contact part cooperating shutdown part has that the contact part with an externally accessible control organ is adjustable and that the coupling device is designed so that the coupling caused by it of the counter in the transition from the first exposure with double exposure recordings to the Film return transport is maintained in a manner known per se (CH-PS 4 92 231)

In other words, the counter has an associated limit switch both in the starting position and in the end position, between which it moves back and forth (during the first exposure or film return transport). In this way it is ensured that the retrieved film length is always exactly the same as the previously advanced film length, regardless of how large this film length is selected in the individual case.
The invention is described in detail below with reference to an exemplary embodiment shown in the drawing; it shows

F i g. 1 is a schematic oblique view of the essentials Parts of the embodiment,

F i g. 2 is a partial sectional view Sn in the direction of the arrow Λ in Fig. 1,

F i g. 3 is a partial sectional view in the direction of the arrow in FIG. 1,
F i g. 4 shows the electrical circuit diagram of the exemplary embodiment and

F i g. 5 is a diagram to facilitate understanding of the mode of operation.

According to FIG. 1, a shutter shaft 1 driven by a reversible motor M is geared to the conventional film gripper (not shown) so that it can transport the film either in the normal take-up direction N or in the rewind direction R. The locking shaft 1 has a sector disk 2 and a worm 3 seated on it. The worm 3 is constantly in engagement with a worm wheel 4 which is in torsionally rigid connection with a coupling wheel 5 via a shaft 6. The shaft 6 is rotatably mounted on a support arm T which extends upwards from a slide 7. The clutch wheel 5 can mesh with a counting wheel 15. The slide 7 is guided parallel to the locking shaft 1 on pin 8 fixed to the camera. The slide 7 is biased in the direction of the arrow X by a spring *. A cylindrical cam 10, a changeover switch 11 provided with the necessary switching contacts for reversing the direction of rotation of the motor and a changeover adjusting disk 12 sit on a common shaft 13, so that a rotation of the adjusting disk 12 actuates the changeover switch 11 and causes the cylindrical cam component 10 to rotate . The I 'mschalt-setting disc 12 is provided with Einstellsymbolen "1", "N", "2" and "R" (not shown) which cooperate with a fixed mark device fourteenth

As shown, the cylindrical cam 10 is designed so that it engages the slide 7 in FIG. 1 is moved to the left and thereby the coupling wheel 5 is lifted off the counting wheel 15 when the adjusting disk 12 is rotated so that its setting symbol "N" is on the marking

14 is aligned The cylindrical cam 10 is also designed so that it the slide 7 after moved right to the clutch wheel 5 with the counting wheel

15 to be brought into engagement when the adjusting disc 12 with the setting symbol “1” or “2” on the marking 14 is set.

The switching contacts of the changeover switch U act like this. that when the setting symbol "N" is set on the marking 14, the motor M for a drive is switched in the normal recording direction of rotation, ie in the film winding direction (cf. the one with continuous

ω) lines shown in Fig. 4 contact position). This also applies if the setting symbol “1” or “2” on the adjusting disc 12 is aligned with the marking 14. In addition, the switching contacts in changeover switch U are designed so that when the setting symbol »R« is set

The motor M is switched to reverse on the marking 14, ie the film is rewound (cf. dashed positions of the contacts in the circuit diagram according to FIG. 4).

The counting wheel 15 sits on a shaft 19 and rotates either in the normal or in the reverse direction. the Normal direction of rotation of the counting wheel 15 is shown in FIGS. 1 and 2 shown with a solid arrow, and the Return direction with a dashed arrow. A pin 16 is on the front face of the counting wheel 15 attached and on the rear end face (see FIG. F i g. 2 and 3) a line plate 20 is attached to the While 19 also sits a counting dial 15 ', which carries a scale 15 "The counting wheel 15 and the Counting dial 15 'can be made in one piece (see FIG. 3). An adjusting member 17 for adjusting the Return position of the pin 16 is attached to the camera body and has essentially the same width as the diameter of the pin 16. A return spring 18 is attached to the counting wheel 15 so that they between their ends the pin 16 and the adjusting member 17 in the in F i g. 1 holds the starting position shown, the counting wheel 15 and the dial 15 'carrying Shaft 19 is rotatably mounted on camera body 27 and is held by a friction spring 30 (FIG. 3). The on The head of the shaft 19 lying on the dial side jumps outward from the camera body and can be turned from the outside by hand into any desired position in which the shaft The head of the shaft 19 is fastened in each case with respect to the camera body under the action of the friction spring 30 bears a marking 19 'which corresponds to the counting scale 15 "attached to the counting dial 15' cooperates.

The line plate 20 attached to the other end face of the counting wheel 15 has an outer one conductive area 20 "and an inner conductive area 20 '. The outer area 20" forms the Contact track for a wiper 25 on the line plate 20, and the inner region 20 'forms the Contact track for wiper 21 and 24 on the line plate 20. Small insulating pieces 22 and 23 are on the inner contact track 20 'of the line plate 20 is provided. The grinders 24 and 25 are on Camera body attached with the interposition of an insulator 26. The contact 25a of the wiper 25 is made always in a conductive connection with the outer contact track 20 ″. The wiper 25 is connected to via a line one of the connections of the motor M electrically connected.

The contact 24a of the wiper 24 is partly with the inner contact track 20 'and partly with the insulating piece 23 in contact. The grinder 24 is (see Fig. 4) on the one hand via the grinder 25 to one connection of the motor M and on the other hand via a line with the return circuit of the switch 11 is connected.

A wiper 21 is insulated by an insulating member 31, attached to the shaft 19. The contact 21a of the wiper 21 is partly in contact with the inner contact track 20 'of the line plate 20 and partly with the insulating piece 22 (FIG. 2). The wiper 21 is (see FIG. 4) connected on the one hand via the wiper 25 to one connection of the motor M and on the other hand via a line to the circuit for the normal direction of rotation of the switch 11. The other connection of the motor M is connected via a line together with the circuits assigned to the changeover switch 11 for the normal and reverse direction of rotation of the motor. At the end of the first exposure in double exposure photography, the grinder 21 stands on the insulating piece 22 and at the start of such Exposure is the grinder 24 on the insulating piece 23 (Fig.2). The insulating pieces 22 and 23 cooperate with the conductor plate 20 and the wiper 21 in such a way that they form a kind of time switch. • j In addition, a voltage source 28, z. B. a battery, and a start switch 29 is provided which is operationally assigned to the shutter release button of the camera

The mode of action is as follows: Normal photography

The adjusting disk 12 is set by hand to the marking 14 with its setting symbol “/ V”. This moves the slide 7 (FIG. 1) to the left

ii shifts and moves the clutch wheel 5 from the counting wheel 15, while the switch 11 closes the circuit for driving the motor M in the normal direction, ie the film winding direction. The grinders 21 and 25 are located on the inner and outer

vi contact tracks 20 'and 20 "of the lead plate 20 (Fig. 2). When the start switch 29 is then closed, the film take-up shaft (not shown) and the shutter shaft 1 are rotated and the associated film gripper (not shown) driven, whereby the

2S film is normally exposed and wound up.

Double exposure photography

The adjusting disc 12 is indicated with its setting symbol »1« set to marker 14 This will set the Slide 7 moved to the right to bring the clutch wheel 5 with the counting wheel 15 into engagement, while the changeover switch 11 closes the circuit for driving the motor M in the normal direction of rotation, ie in the film winding direction, the grinder 21 and 25 are in contact with the inner and outer contact tracks 20 'and 20 ", during the Slider 24 on the insulating piece 23 is to interrupt the associated circuit. If the Start switch 29 is closed, the (not

-to shown) film take-up shaft together with the shaft 1 and the associated film gripper (also not shown) to pick up the film for the first exposure to be transported further (see Fig. 5). During this time, the counting wheel 15 is also in the normal direction Rotated (clockwise in FIG. 2) so that the pin 16 is rotated in the same direction against the force of the spring 28. Soon thereafter, the insulating piece 22 runs under the wiper 21, whereby the circuit of the motor M is opened and this is stopped. This quits

so the first exposure. The length of the film strip subjected to the first exposure can be measured on a scale of 15 " can be read at the marking 19 '. The insulating piece 23 is no longer under the grinder 24, this is therefore now in contact with the contact path 20 '.

Next, the adjusting disc 12 with its symbol "R" is set to the marking 14. The slide 7 remains in the same position as when the adjusting disc 12 was previously set to "1" so that the Knpplrungsrad 5 remains in engagement with the counting wheel 15 only the changeover switch 11 is switched and closes the circuit for the reverse direction of rotation of the motor M, ie for the film reverse direction. Also, as mentioned, the

there is wiper 24 in contact with the contact track 20 ' Therefore, the start switch 29 is closed, the take-up shaft and associated film gripper are rotated in the reverse direction to return the film (Fig. 5).

to fetch. At the same time, the counting wheel 15 is also rotated backwards (counterclockwise in FIG. 2), with the pin 16 also rotating. Shortly thereafter, the grinder 24 runs onto the insulating piece 23 and interrupts the circuit for the motor return. The motor M stops and the film is brought back to the starting position on the first exposure. The length of filmstrip retrieved in this way is equal to the length that was unwound during the first exposure, and the starting position prior to the first exposure is in exact correspondence with the ending position of the retrieved film. At this time, the insulating piece 22 has moved away from the grinder 21 again; this is therefore in contact with the inner contact track 20 ′ of the line 20. The subsequent setting of the adjusting disk 12 with its setting symbol “2” (or “1”) on the marking 14 does not affect the position of the slide 7, so that the coupling wheel 5 remains in engagement with the counting wheel 15. In contrast, the changeover switch 11 is switched over and closes the circuit (solid line in FIG. 4) for the normal direction of rotation of the motor M, ie for a film movement in the winding direction. The grinder 21 is still in contact with the contact path 20 'of the line plate 20. When the start switch 29 is then closed, the film take-up shaft and associated film gripper are rotated in the normal direction, and the film is fed for a second exposure, a dissolve (cf. Fig. 5), wound up. At the same time, the counting wheel 15 is also rotated in the normal direction and the pin 16 is taken along in the same direction against the force of the spring 18. Soon thereafter, the insulating piece 22 runs under the wiper 21 and interrupts the circuit. Therefore, the motor M is stopped and the second exposure is ended. The length of the filmstrip subjected to the second exposure can be read off the counting scale 15 "at the marking 19 '. This filmstrip length is equal to the length of the film exposed to the first exposure, and the stop position of the film corresponds exactly to the end position

to at the first exposure (see Fig. 5).

If another scene is to be “photographic”, the adjusting disk 12 is rotated until its symbol “N” is set on the marking 14. Here, the clutch wheel 5 lifts off the counting wheel 5 in the manner described above; the latter therefore rotates back into its starting position (FIG. 2) by the force of the spring 18. The wiper 21 comes into contact with the inner contact path 20 ′, while the wiper 24 rests on the insulating piece 23. When the start switch 29 is closed, a lingering normal exposure process is triggered, which takes place in the manner described above.

By manually turning the externally accessible head of the shaft 19 around the grinder 21 accordingly to adjust, the film length exposed by the double exposure method described above can be any preselectable value can be set.

The counting wheel 15 can also be a linear link,

z. B. a rack, can be replaced, which can come into engagement with the clutch wheel 5 '.

1 sheet of drawings

Claims (4)

Patent claims: 1. Double exposure control device for a motion picture camera, the drive motor of which can be reversed in the direction of rotation, with a double exposure control device for the motor drive by a to be operated coupling device attachable film length measuring and limiting mechanism, the one in the coupled state is proportional to the film transport from an initial position to a Endstetlung having movable counting member, the endstelking being defined by a limit switch for the drive motor which can be actuated by the counting member, characterized in that an is further, the starting position of the counter (15) assigned and operated by this switch (23, 24) is provided that the End position of the counter (15) for the double exposure defining limit switches (21,22) on Camera body (27) adjustably mounted and moved relative to the counter (15) with the has adjustably mounted contact part (21) interacting shutdown part (22) that the Contact part (21) is adjustable with an externally accessible actuator (19), and that the coupling device (10) is designed so that the coupling brought about by them (at 5) of the counting element (15) also during the transition from the first Exposure for double exposure exposures on the film return transport in a manner known per se is maintained 2. Apparatus according to claim 1, characterized in that the counting member than on the camera body rotatably mounted on a shaft (19) wheel (15) is formed, the end face with a circuit board (20) provided as contact tracks (20 ', 20 ") for static grinders (21,24,25) resting thereon is that in the contact track (20) of two (21,24) of the wiper two insulating pieces (22, 23) are provided are, in conjunction with the grinders, the limit switch (23,24) in the starting position and form the limit switch (21, 22) for the end position of the counting wheel, and that the grinder (21) of the the latter on the camera body (at 19) adjustable «is mounted. 3. Apparatus according to claim 2, characterized in that the adjustability of the one grinder (21) is accomplished by its torsionally rigid attachment to the counting wheel bearing shaft (19), which is in turn adjustable in the rotary position and designed as an externally accessible actuator. 4. Device according to one of claims 1 to 3, characterized in that to facilitate Presetting of the desired cross-fade length the counter element (15) a scale component (15 ', 15 ") that cooperates with a reference mark (19 ') on the actuator (19).